Until now, the majority of this blog has been focused on the nanoparticulate applications of various polymers and some metals. There are, however, many other unique material types that can be used to great effect in nano-bioapplications. Ceramics and bioglasses are particularly useful in the areas of joint and bone repair.

Ceramic materials are inorganic, nonmetallic, and characterized by ionic bonds and crystalline structures with long-range order. Bioglass materials are also comprised of ionic bonds but are structurally amorphous and exhibit short-range order.

Because they can be made of the same components in bone (calcium phosphates), ceramics have unique osteoinductive, osteoconductive, and osteointegrative properties which lend themselves well to bone repair. Osteoinductive materials promote new bone growth by recruiting stem cells and causing their specialization into bone-related cells such as osteoclasts, osteoblasts, or osteocytes. Osteoconductive materials promote the growth of existing bone while osteointegrative materials provide scaffolds in which new or existing bone can grow.

Common ceramic materials used in bioapplications include Alumina (AlO₃), zirconium, hydroxyapatite, calcium phosphates, and various composite materials. Bioglasses are commonly made from different combinations of silica (SiO₂), calcium oxide (CaO), and sodium oxide (Na₂O). Ceramics and bioglasses are characteristically bioinert.

Ceramic nanoparticles, or Nanoceramics, have unique properties due to their structure and small size. Unlike conventional bulk ceramics, nanoceramics can exhibit superplasticity and bioactivity due to their fine grain size and controllable crystallinity. They are typically manufactured by a process called chemical solution deposition, also known as sol-gel. They can manifest certain electrical or magnetic properties, being dielectric, ferroelectric, ferromagnetic, and even superconductive. Mesoporous bioactive glasses have shown excellent characteristics as drug-carrying bone regeneration materials and as nanoparticles.

Nanoceramics have been used to make a material called nanotruss, which is more than 85% air extremely light, strong, and flexible. The fractal nanotruss is a nanostructure architecture made of alumina or aluminum oxide. Its unique property is that it can compress to a small fraction of its original volume and recover its shape without any structural damage after applied forces are removed.

Micro-bioglasses have found applications in dental care and can be found in common products such as Sensodyne. In the presence of saliva and water, a calcium phosphate layer can crystallize to form hydroxyapatite in tiny holes in teeth that allow hot or cold sensations to reach nerves and cause pain. The treatment of sensitive teeth with microparticulate bioglasses is called NovaMin and is an example of the bioregenerative properties of bioglasses.

The study of micro and nanoceramics and bioglasses is a growing field and promises to reveal ever more creative and useful applications to better human health. The interesting magnetic and electrical properties of nanoceramics are particularly noteworthy for their potential use in the electronic industry and applications in room temperature superconductors, a revolutionary theoretical technology.